Perhaps you should try some spelling variations:
passiv » massiv, passiven, passiver
passivierender » massivierender, passivenierender, passiverierender, passivierende, aktivierender, passivieren
passivenerwerb » massivenerwerb, passivenenerwerb, passiverenerwerb, passiverwerb
passive » massive, passivene, passivere

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((passiv OR (passivierender OR passivenerwerb)) OR passive).
• Adding a wildcard symbol may retrieve word variants: ((passiv or (passivierender or passivenerwerb)) or passive)*.